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Question

我正在尝试通过混音从open-zeppelin部署this示例

这是代码。我部署了令牌合同，然后将地址作为众包合同的输入。我尝试在remix中更改编译器版本。不确定需要哪个版本。

pragma solidity ^0.5.11;

import "https://github.com/OpenZeppelin/openzeppelin-contracts/contracts/crowdsale/validation/CappedCrowdsale.sol";
import "https://github.com/OpenZeppelin/openzeppelin-contracts/contracts/crowdsale/distribution/RefundableCrowdsale.sol";
import "https://github.com/OpenZeppelin/openzeppelin-contracts/contracts/crowdsale/emission/MintedCrowdsale.sol";
import "https://github.com/OpenZeppelin/openzeppelin-contracts/contracts/token/ERC20/ERC20Mintable.sol";
import "https://github.com/OpenZeppelin/openzeppelin-contracts/contracts/token/ERC20/ERC20Detailed.sol";

/**
* @title SampleCrowdsaleToken
* @dev Very simple ERC20 Token that can be minted.
* It is meant to be used in a crowdsale contract.
*/
contract SampleCrowdsaleToken is ERC20Mintable, ERC20Detailed {
  constructor () public ERC20Detailed("Sample Crowdsale Token", "SCT", 18) {
    // solhint-disable-previous-line no-empty-blocks
  }
}

/**
* @title SampleCrowdsale
* @dev This is an example of a fully fledged crowdsale.
* The way to add new features to a base crowdsale is by multiple inheritance.
* In this example we are providing following extensions:
* CappedCrowdsale - sets a max boundary for raised funds
* RefundableCrowdsale - set a min goal to be reached and returns funds if it's not met
* MintedCrowdsale - assumes the token can be minted by the crowdsale, which does so
* when receiving purchases.
  *
  * After adding multiple features it's good practice to run integration tests
  * to ensure that subcontracts works together as intended.
  */
contract SampleCrowdsale is CappedCrowdsale, RefundableCrowdsale, MintedCrowdsale {
  constructor (
    uint256 openingTime,
    uint256 closingTime,
    uint256 rate,
    address payable wallet,
    uint256 cap,
    ERC20Mintable token,
    uint256 goal
  )
    public
    Crowdsale(rate, wallet, token)
    CappedCrowdsale(cap)
    TimedCrowdsale(openingTime, closingTime)
    RefundableCrowdsale(goal)
  {
    //As goal needs to be met for a successful crowdsale
    //the value needs to less or equal than a cap which is limit for accepted funds
    require(goal <= cap, "SampleCrowdSale: goal is greater than cap");
  }
}

当前，我收到上述错误。我在做什么错了？